[FFmpeg-user] Set keyframe interval raw video

[Anatol]

On Thu, Oct 20, 2016 at 12:13 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
wrote:

> 2016-10-20 10:38 GMT+02:00 Gabor Alsecz <alseczg at gmail.com>:
> > Dear All,
> >
> > Would like to know what is the best way/parameter to force key frame
> > interval. I would need 2*FPS
> > I'm feeding FFmpeg's stdout with raw images at fps 25.
>
> > So far i have the following command:
>
> > ffmpeg -y -loglevel info  -f lavfi -i aevalsrc=0  -f rawvideo  -pix_fmt
> > rgb24 -video_size 1280x720 -framerate=25 -i "-"  -f flv -acodec aac
> -vcodec
>
> I don't think this is supposed to work.
>
> > h264_nvenc  -profile:v high -vf "fps=25,format=yuv420p" -minrate 3000k
>
> Careful with the fps filter: If input fps == output fps, don't use it to be
> on the safe side.
>
> > -maxrate 3000k -bufsize 6000k output.mp4
>
> -g should set the keyframe interval.
>
> Carl Eugen
>

Carl,
Why we should be careful with the fps filter?
What's wrong with it?

Anatol